THE BREEDING SEASON IN S.W. ECUADOR

The breeding season on the Santa Elena peninsula in S.W. Ecuador is described on the basis of 1761 nests found in the four years 1955 to 1958. The environment and climate are outlined—a cool, dry season from about May to November and a warm, variable wet season from December to April, when alone rain may fall. It is shown that each year the general breeding season is closely correlated with the rainfall. The peak of breeding varies from year to year by at least a month and its length from about six weeks to three and a half months.
Although all species for which there are enough data, are stimulated to breed after important falls of rain, most of those species of small land-birds which are completely resident, attempt to nest before the rain and often continue for some time afterwards. Some specific differences, between seed- and insect-eating finches, seem to be adaptations to food supply and the availability of nest sites and building material. Such evidence as there is suggests that raptors, waders and waterfowl also nest in the wet season (often late), rather than in the dry season. (Unfortunately herons and sea-birds do not nest in the area.)
Annual differences in the amount of breeding by the same species are thought not to be entirely due to differences in weather between years.
It is suggested that the late (August-September) breeding in the Galápagos Islands described by Lack (1950) and the apparent dry-season nesting of raptors, waders and waterfowl there might be found to be linked with variable or abnormally wet weather, if records of rainfall from the islands were available.     

BIRDS OF THE UNDERSTORY OF LAKE-SHORE FORESTS ON THE ENTEBBE PENINSULA, UGANDA

Monthly mist-netting of low-flying forest birds was conducted in three lake-shore forests in southern Uganda from September 1970 to July 1972. It was found that the edge of the forest formed a distinct ecological barrier that was rarely crossed by species on either side of it. Catches were concentrated in the hours of daylight, in two peaks, a morning peak at 09.00 hrs and an afternoon peak at 16.00 hrs (sun-time) for all birds combined, although there were slight species differences. Most bird species were found to be sedentary in a fixed home-range, and covered lateral distances of up to c. 300 m. No movement between the different forests was recorded.
The most common birds such as bulbuls were often caught at heights between 0·6 and 1·8 m above the ground, but the upper limit of their vertical range was not determined. It is suggested that the bi-modality of flight activity may be intrinsic, even though it may be correlated with such extrinsic factors as light and radiation. On a month to month basis, the numbers of birds caught reflected breeding and moult activity. This was best shown by the Pygmy Kingfisher, taken in higher numbers towards the end of the first rainy season when a majority of the birds caught were young and many birds were moulting the remiges. On the other hand higher numbers of Olive Sunbird were found during the second rainy season, again at a time corresponding to a general moulting of remiges. The bulbuls showed fluctuations in numbers caught that were matched by an equally fluctuating pattern of moult. The role of food as a possible limiting factor in bird breeding is discussed.     

3. THE BIRDS OF LADYSMITH,NATAL

Catry, P., Araújo, A., Cruz, C., Pinheiro, A., Poças, M., Nadum, J., Armelin, M.&; Pereira, J.R. 1999. Are mist-nets suitable for rapid habitat evaluations in the tropics? Results from a study in Guyinea-Bissau. Ostrich 70(2) 134–137

There is an increasing need for rapid habitat evaluations, in the tropics, for conservation purposes. Biodiversity is often assessed by studying relatively well known groups, such as birds. But even birds can be difficult to watch and identify in tropical habitats. Mist-netting is relatively free of observer bias, and allows sampling effort to be standardised. We sampled birds by mist-netting in seven wooded habitats, covering a wide range of levels of anthropogenic disturbance, in the Cufada region, Guinea Bissau. Capture rates, species diversity (as estimated by rarefaction) and originality of the bird communities appeared to be higher in disturbed habitats. Primary forest had the lowest capture rate and the lowest diversity index. Originality was also very low in primary forest. We discuss several possible causes for these patterns and argue that surveys based exclusively on mist-netting can be severely misleading, when comparing bird communities in different habitats.     

5. BIRDS OF THE DONGAS

Elliott, C. C. H. 1974. Sixteenth ringing report for Southern Africa. Ostrich 45:161-166.

A report of ringing activities in Southern Africa from 1 July 1970 to 30 June 1973 is presented. The newly founded South African National Unit for Bird-Ringing Administration now produces comprehensive computer print-outs of ringing and recovery information and as a result this published report is highly condensed. Details of the totals of palaearctic migrants ringed and recovered are given together with those from the major studies, past and present, on ethiopian species.